I can’t seem to figure out what is wrong with my gl650 carbs. They won’t stop leaking fuel like crazy. I’ve forgotten how many times I’ve rebuilt them with the same result. Start it runs fine no leaking fuel, turn fuel off and set aside for 10-15 min turn fuel on restart and it just starts flowing out like crazy. I’ve cleaned the carbs many many times, changed the float pin, cleaned the brass where the float pin’s slide. Still the same result. Also, I’m using a cx500 c or d tank (the café style tank.) Only thing I can think of is the cross over tube is causing a problem aka leaking or I’m not blocking off the correct tubes that originally went to the petcock on the gl650 tank because that tank used a pressured style petcock? Anyone have any ideas?

Have you checked the overflow pipe/tube in the float bowls? Those have been known to get hairline cracks and leak even when the floats don't stick. Sometimes you can't see the cracks, but they are easy to repair with some solder.

This diagram shows how the vacuum petcock lines are routed, and if you are now using a modified vacuum petcock as a manual petcock, then you need to block off the nipple on the right carb toward the engine, and also block off the forward petcock nipple. This is assuming you have the vacuum petcock still. If not, then plugging off the nipple on the carb should do it. You might also make sure you used the proper bowl gaskets during the rebuilds.